1. Field of the Invention
The present invention relates to an imaging device and imaging method and program to recognize a subject and control imaging operation on the basis of the motion of the subject.
2. Description of the Prior Art
An imaging device such as a digital camera or a digital video camera with an auto shutter function has been widespread. The auto shutter function is to shoot a subject at arbitrary timing automatically or in a predetermined time after a full press of the shutter button.
In conventional automatic shooting, a problem may occur that if a user shoots himself or herself after setting a camera and pressing a shutter button, the shooting may be completed before the user is ready for being shot or the user has to wait for the shutter to click after he or she is ready for being shot.
Further, an imaging device which can release the shutter with a remote control has been developed. However, a user may forget to carry a remote control or find it troublesome to carry it with him or her all the time.
In view of the above problems, Japanese Patent Application Publication No. 2010-74735 discloses an imaging device having an automatic shutter control function in accordance with the blinking of the eyes of a subject, for example. This imaging device sets the order of priority when capturing multiple subjects or faces to recognize the motion of a subject's face with a high priority or to output a control signal in accordance with a combination of the opening and closing of the eyes of the high-priority subject.
However, the above technique faces a problem that it is difficult to recognize the motion of a part of a small face when the subject is at a long distance from the imaging device. For example, generally, a group photograph is taken at a relatively long distance with a wide-angle zoom and the size of the individual faces captured tends to be small. Under such shooting condition, even if the faces are accurately detected, it is very hard to accurately recognize a change in a part of the faces such as blinking eyes, making automatic shooting control unfeasible.
To recognize the motion of a part of the faces accurately, the subjects need to be close to the imaging device or their faces need to be imaged in a certain size or more, using a telephoto zooming.
Further, Japanese Patent Application Publication No. 2011-78009 discloses an imaging device configured to detect a subject's face or gesture from an image. This imaging device detects a facial image from image data and detects a hand image in association with the facial image to control imaging operation in accordance with the shape or motion of the detected hand image.
However, it is disadvantageous that the imaging device requires an enormous amount of information as data on the position of a body part, color data, size data, and texture data to accurately recognize a subject's gesture. Also, it takes a huge amount of time and load on the device to process the enormous amount of data. Moreover, since the ways of gesturing, the color of skin, and the shapes and sizes of a body part are different depending on an individual, even the enormous amount of data may not be sufficient to accurately recognize someone's gesture.